This is a preview - click here to buy the full publication IEC IEC 60865-1 Edition3.0 2011-10 INTERNATIONAL STANDARD NORME INTERNATIONALE Short-circuit currents - Calculation of effects - Part 1: Definitions and calculation methods Courantsdecourt-circuit-Calcul deseffects- Partie 1: Definitions et methodes de calcul INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE PRICECODE XA CODEPRIX ICS17.220.01;29.240.20 ISBN 978-2-88912-771-9 ? Registered trademark of the International Electrotechnical Commission Marque deposee de la Commission Electrotechnique Internationale This isapreview-clickheretobuythefull publication - 2 - 60865-1@IEC:2011 CONTENTS FOREWORD... Scope... 1 ..6 2 Normative references ... 3 Terms, definitions, symbols and units.. 3.1 Terms and definitions... 3.2Symbols and units.... General. 4 5 Rigid conductor arrangements.. .13 5.1 General.... 5.2 Calculation of electromagnetic forces .. .13 5.2.1 Calculation of peak force between the main conductors during a three.phase short..circuit...................... 5.2.2 Calculation of peak force between the main conductors during a line- to-line short-circuit.. 5.2.3 Calculation of peak value of force between coplanar sub-conductors...... 14 5.3 Effective distance between main conductors and between sub-conductors.. .14 5.4 Calculation of stresses in rigid conductors.. .16 5.4.1 Calculation of stresses.. .16 5.4.2 Section modulus and factor g of main conductor composed of sub- conductors.. ..17 5.4.3 Permitted conductor stress. ..20 ..21 5.5 Structure loads due to rigid conductors 5.6 Consideration of automatic reclosing... .21 5.7 Calculation with special regard to conductor oscillation .... ....22 5.7.1 General.. 5.7.2 Determination of relevant natural frequency..... 5.7.3 The factors VF, Vom, Vos, Vrm and Vrs . Flexible conductor arrangements... 6 ...26 6.1 6.2 Effects on horizontal main conductors . 6.2.1 General... 6.2.2 Characteristic dimensions andparameter. .27 6.2.3 Tensile force Ftd during short-circuit caused by swing out (short- circuit tensile force) without dropper in midspan ..... 6.2.4 Dynamic change of sag due to elongation of conductor and change of shape of the conductor curve.... 6.2.5 Tensile force Ft.d during short-circuit caused by swing out (short- circuit tensile force) with dropper in the middle of the span............32 6.2.6 6.2.7 6.3 Effects on vertical main conductors (droppers).... .....34 6.4 Effects on bundled conductors ... ...35 6.4.1 Characteristic dimensions and parameter.. ..35 6.4.2 Tensile force Fpi,d in the case of clashing sub-conductors.... ...38 6.4.3 Tensile force Fpi,d in the case of non-clashing sub-conductors ... 6.5 Structure loads due to flexible conductors ........ 6.5.1 Design load for post insulators, their supports and connectors ..... Thisisapreview-clickheretobuythefull publication 60865-1@IEC:2011 - 3 - 6.5.2 Design loadfor structures,insulators and connectors withtensile forcestransmittedbyinsulatorchains .41 6.5.3 Design loadforfoundations. ...42 Thethermal effectonbareconductors ..42 7 7.1 General. .42 7.2 Calculation of thermal equivalent short-circuit current 7.3 Calculation of temperature rise and rated short-time withstand current density for conductors ..43 7.4 Calculation of thermal short-time strength for different durations of the short- circuit ..44 AnnexA(normative)Equationsfor calculation of diagrams Bibliography. .51 Figure 1-Factor k1s for calculating the effective conductor distance. 15 Figure 2-Loading direction and bending axis for multiple conductor arrangements. ...18 Figure 3-Factor e for the influence of connecting pieces in Equation (17) .24 Figure 4 - Factors Ve, Vom and Ves to be used with the three-phase and line-to-line short-circuits... .25 Figure 5 -Factors Vrm and Vrs to be used with three-phase automatic reclosing. ...26 Figure 6 - Maximum swing out angle Smax for a given maximum short-circuit duration Tk1 ...30 Figure 7-Factor yfor tensile force in